; 16-bit binary to BCD conversion 
; pete griffiths 2007
; http://picprojects.org.uk/projects/pictips.htm
;
; These file register variables will
; need to be defined elsewhere.
; binH
; binL
; bcdH
; bcdM
; bcdL
; counter
; temp
;
; binH, binL contain the binary value to
; convert. Conversion process destroys contents.
; Result is in bcdH, bcdM, bcdL on return.
; Call _bin2bcd to perform conversion.
;
; Executes in 454 instructions


_bin2bcd    movlw     d'16'
            movwf     counter
            clrf      bcdL
            clrf      bcdM
            clrf      bcdH 

 _repeat    rlf       binL,F
            rlf       binH,F
            rlf       bcdL,F
            rlf       bcdM,F
            rlf       bcdH,F

            decfsz    counter,F
            goto      _adjust
            return

_adjust     movlw     d'14'
            subwf     counter,W
            skpnc 
            goto      _repeat
            movfw     bcdL
            addlw     0x33
            movwf     temp
            movfw     bcdL
            btfsc     temp,3
            addlw     0x03
            btfsc     temp,7
            addlw     0x30
            movwf     bcdL
            movfw     bcdM
            addlw     0x33
            movwf     temp
            movfw     bcdM
            btfsc     temp,3
            addlw     0x03
            btfsc     temp,7
            addlw     0x30
            movwf     bcdM
            goto      _repeat
; we only need to do the test and add +3 for
; the low and middle bcd variables since the
; largest binary value is 0xFFFF which is
; 65535 decimal so the high bcd byte variable
; will never be greater than 6.
; We also skip the tests for the first two
; shifts.